Gut microbiota metagenomics in aquaculture: factors influencing gut microbiome and its physiological role in fish

Fish gut microbiome confers various effects to the host fish; this includes overall size, metabolism, feeding behaviour and immune response in the fish. The emergence of antimicrobial-resistant (AMR) bacteria and hard to cure fish diseases warrant the possible utilization of gut microbes that exhibits a positive effect on the fish and thus lead to the usage of these microbes as probiotics. The widespread and systematic use of antibiotics has led to severe biological and ecological problems, especially the development of antibiotic resistance that affects the gut microbiota of aquatic organisms. Probiotics are proposed as an effective and environmentally friendly alternative to antibiotics, known as beneficial microbes. At the same time, prebiotics are considered beneficial to the host's health and growth by decreasing the prevalence of intestinal pathogens and/or changing the development of bacterial metabolites related to health. Uprise of sequencing technology and the development of intricate bioinformatics tools has provided a way to study these gut microbes through metagenomic analysis. From various metagenomic studies, ample of information was obtained; such information includes the effect of the gut microbiome on the physiology of fish, gut microbe composition of different fish, factors affecting the gut microbial composition of the fish and the immunological effect of gut microbes in fish; such this information related to the fish gut microbiome, their function and their importance in aquaculture is discussed in this review

Elicitation of the in vitro Cultures of Selected Varieties of Vigna radiata L. With Zinc Oxide and Copper Oxide Nanoparticles for Enhanced Phytochemicals Production

This study was conducted to develop a protocol for in vitro shoot multiplication and callus induction of various mung bean varieties to obtain enhanced phytochemical content with the help of elicitors. For shoot multiplication, two types of explants (shoot tips and nodal tips) of three varieties of mung bean (Mung NCM-13, MgAT-7, and MgAT-4) were used. Both types of explants from in vitro and in vivo sources were cultured on the MS medium supplemented with different concentrations (0.25–3.0 mg/L, increment of 0.5 mg/L) and combinations of BAP and IBA as independent treatments. For callus induction, leaf explants (in vitro source) were cultured on MS medium supplemented with 2,4-D (1–3 mg/L) alone or in combination with BAP or NAA (0.5 and 1.0 mg/L). For the enhanced production of phenolics and glycosides, calli were cultured on MS media supplemented with zinc oxide (0.5 mg/L) and copper oxide nanoparticles (0.5 mg/L) as nano-elicitors. Results showed that in vitro explants responded better in terms of shoot length, number of shoots, and number of leaves per explant when compared to in vivo explants. Moreover, shoot tips were better than nodal explants to in vitro culturing parameters. All three varieties showed the optimized results in the MS medium supplemented with 1 mg/L BAP, while roots were produced only in cultures fortified with 1 mg/L IBA. The leaf explants of in vitro and soil-grown plantlets showed a maximum callogenic response of 90 and 80%, respectively, on MS medium supplemented with 2,4-D (3 mg/ml). Maximum phenolic content (101.4 μg of gallic acid equivalent/g) and glycoside content (34 mg of amygdalin equivalent/g of plant material) was observed in the calli cultured on MS medium supplemented with 3 mg/L of 2,4-D. Furthermore, the addition of zinc oxide (0.5 mg/L) and copper oxide (0.5 mg/L) nanoparticles to the callus culture medium significantly enhanced the phenolic content of Mung NCM-13 (26%), MgAT-7 (25.6%), and MgAT-4 (22.7%). Glycosidic content was also found to be increased in Mung NCM-13 (50%), MgAT-7 (37.5%), and MgAT-4 (25%) varieties when compared to the control. It is suggested that elicitation of in vitro cultures of mung beans with nanoparticles could be an effective strategy for the enhanced production of secondary metabolites

Leaky Gut and Autoimmunity: An Intricate Balance in Individuals Health and the Diseased State

Damage to the tissue and the ruining of functions characterize autoimmune syndromes. This review centers around leaky gut syndromes and how they stimulate autoimmune pathogenesis. Lymphoid tissue commonly associated with the gut, together with the neuroendocrine network, collaborates with the intestinal epithelial wall, with its paracellular tight junctions, to maintain the balance, tolerance, and resistance to foreign/neo-antigens. The physiological regulator of paracellular tight junctions plays a vital role in transferring macromolecules across the intestinal barrier and thereby maintains immune response equilibrium. A new paradigm has explained the intricacies of disease development and proposed that the processes can be prevented if the interaction between the genetic factor and environmental causes is barred by re-instituting the intestinal wall function. The latest clinical evidence and animal models reinforce this current thought and offer the basis for innovative methodologies to thwart and treat autoimmune syndromes

Utilization of Organic Manure for Culture of Cladocerans, Daphnia carinata, Ceriodaphina carnuta and Copepod, Thermocyclops decipiens under laboratory conditions

399-404Mass culture of the cladocerans (Daphnia carinata and Ceriodaphina carnuta) and copepod (Thermocyclops decipiens) was carried out using chicken manure (500ppt) in the medium. The study lasted for twenty-one (21) days. Result showed that total number of individuals produced was highest in C. carnuta culture (10725 ± 846) on 18th day of inoculum using chicken manure. This was significantly different (P<0.05) from D. carinata and T. decipiens cultures. Maximum density of D. carinata (4660 ± 523) and T. decipiens (3706 ± 192) was recorded on 9th and 15th day respectively. pH ranged from 6.2-7.5, 6.5-7.8 and 6.0-7.5 in first, second and third treatments respectively. Optimum density was found when dissolved oxygen level ranged between 4.63-6.43mg/l, 4.08-5.9mg/l and 3.46-5.65mg/l in first, second and third treatments respectively. This study suggests that chicken manure is one of the ideal media for use in zooplankton culture to feed fish larvae

A review on the biology and physiology of loach <em>Misgurnus anguillicaudatus</em> in China

759-765Misgurnus anguillicaudatus (Cantor 1842) is the most common loach in the world, habitually, available in Asian regions like China, Korea, India, and Japan. It lives in streams and rice paddy fields, preferably with a soft muddy bottom. The body of a typical loach is elongated with five pairs of barbs surrounding the mouth, and a single short-based dorsal fin. This species is omnivorous and source of diet usually varies from fish and insects, to plant detritus. The fish spawn multiple times per year during a spawning season that lasts from mid-April until mid-October. M. anguillicaudatus diploid individuals (2n=50) are common in wild populations. Different polyploidy populations have been reported in various locations in China. It has a delicious taste with high nutritional value, used as a traditional Chinese medicine. The most serious problem in both loach hatcheries and farms is bleeding in head, opercula, and lower jaw, swollen muscles, anus, liver, and spleen, and empty intestines. Characterization and expression profiles of tissue-specific immune genes are highly useful in understanding gene functions, tissue physiology, and transcriptomics of M. anguillicaudatus.</em

Nitric Oxide and Strigolactone Alleviate Mercury-Induced Oxidative Stress in <i>Lens culinaris</i> L. by Modulating Glyoxalase and Antioxidant Defense System

Developmental activities have escalated mercury (Hg) content in the environment and caused food security problems. The present investigation describes mercury-incited stress in Lens culinaris (lentil) and its mitigation by supplementation of sodium nitroprusside (SNP) and strigolactone (GR24). Lentil exposure to Hg decreased root and shoot length, relative water content and biochemical variables. Exogenous application of SNP and GR24 alone or in combination enhanced all of the aforementioned growth parameters. Hg treatment increased electrolyte leakage and malondialdehyde content, but this significantly decreased with combined application (Hg + SNP + GR24). SNP and GR24 boosted mineral uptake and reduced Hg accumulation, thus minimizing the adverse impacts of Hg. An increase in mineral accretion was recorded in lentil roots and shoots in the presence of SNP and GR24, which might support the growth of lentil plants under Hg stress. Hg accumulation was decreased in lentil roots and shoots by supplementation of SNP and GR24. The methylglyoxal level was reduced in lentil plants with increase in glyoxalase enzymes. Antioxidant and glyoxylase enzyme activities were increased by the presence of SNP and GR24. Therefore, synergistic application of nitric oxide and strigolactone protected lentil plants against Hg-incited oxidative pressure by boosting antioxidant defense and the glyoxalase system, which assisted in biochemical processes regulation

Survey of the reptilian fauna of the Kingdom of Saudi Arabia. V. The lizard fauna of Turaif region

Turaif area located in the Northern border region of Saudi Arabia is one of the most important regions of the Kingdom. This work was proposed to throw light on the diversity of lizard fauna investigated through the collection and subsequent identification of specimens from different localities of Turaif region of Kingdom of Saudi Arabia. Sixteen species of lizards belonging to 5 families (Agamidae, Gekkonidae, Lacertidae, Scincidae and Varanidae) were recorded. Lacertidae was the most common family. Three species of lizards namely Acanthodactylus orientalis, Acanthodactylus scutellatus and Acanthodactylus grandis were reported for the first time in the Turaif region of Saudi Arabia. The geographical distribution of the collected species within this province was mapped

Effect of Feed Quality on Growth and Survival of Striped Snakehead, Channa striatus (Bloch, 1793) Hatchlings

105-110Present study focuses on growth performance of C. striatus using different feeding regimes of live feed and formulated feed. Murrels, belonging to the family Channidae, are widely known as snakeheads. Larviculture of murrels is a herculean task as they are carnivorous and piscivorous with cannibalistic behaviour. Artemia nauplii and rotifers are required for the best survival and growth of C. striatus during the early nursery management, and a combination of fish meal, Artemia nauplii and zooplankton was considered as the overall best diet for larviculture of murrels